PROJECT SUMMARY Preclinical Validation of Dual-Modal Nanotherapy for Chronic Myeloid Neoplasms and Beyond Multiple pathological pathways concomitantly contribute to cancer development and progression. Single-modal therapies for cancer are ineffective and often lead to resistance against the therapies. To achieve our long-term goal of developing an effective and safe therapy for hematologic malignancies, the objective of this study is to pre-clinically validate the targeted therapeutic effects of combination gene therapy and tyrosine kinase inhibition, which function through simultaneously tackling multiple pathological pathways associated with cancer. This study hypothesizes that simultaneously upregulating a pro-apoptotic protein, BIM, and silencing a pro-survival protein, MCL-1, particularly in combination with a BCR-ABL or JAK1/2 tyrosine kinase inhibitor (TKI), will effectively eradicate BCR- ABL+ (Philadelphia chromosome-positive [Ph+]) and Ph- JAK2V617F+ leukemia, respectively, in physiologically-relevant syngeneic and patient-derived xenograft animal models. This approach also minimizes the chance of developing drug-resistance. Guided by strongly supportive preliminary results using viral/nonviral chimeric nanoparticles (ChNPs) consisting of a BIM-encoding adeno-associated virus (AAV) at the core and a MCL-1 siRNA encapsulating, acid-degradable polymeric shell, the central hypothesis will be tested by pursuing specific aims to demonstrate 1) enhanced imatinib (BCR-ABL inhibitor) therapy for BCR-ABL+ leukemia by ChNPs, and 2) inhibited JAK2V617F+ MPN in combination with ruxolitinib (JAK1/2 inhibitor), using preclinical models that closely simulate clinical myeloid neoplasms. This study is expected to develop highly effective, molecularly targeted, and synergistic therapies for hematological malignancies using conventional (TKI) and emerging (gene therapy for multiple pathways) therapeutic modalities. This research is innovative because it will develop a dual- modal therapy (gene and chemotherapy; two genes simultaneously expressed and silenced) using virus/polymer hybrid gene carriers in combination with a synthetic drug. The significance of this study is the development and validation of effective, targeted, and synergistic cancer therapies that addresses current clinical challenges. The paradigm to be explored in this study can make a prolonged impact on developing efficient and safe therapies for a broad range of diseases that are often attributed to multiple abnormal pathways.